import tables, strutils, macros, critbits
import types, parser, interpreter

proc isSymbol*(s: MinValue): bool =
  return s.kind == minSymbol

proc isQuotation*(s: MinValue): bool = 
  return s.kind == minQuotation

proc isString*(s: MinValue): bool = 
  return s.kind == minString

proc isFloat*(s: MinValue): bool =
  return s.kind == minFloat

proc isInt*(s: MinValue): bool =
  return s.kind == minInt

proc isNumber*(s: MinValue): bool =
  return s.kind == minInt or s.kind == minFloat

proc isBool*(s: MinValue): bool =
  return s.kind == minBool

proc newVal*(s: string): MinValue =
  return MinValue(kind: minString, strVal: s)

proc newVal*(s: cstring): MinValue =
  return MinValue(kind: minString, strVal: $s)

proc newVal*(q: seq[MinValue]): MinValue =
  return MinValue(kind: minQuotation, qVal: q)

proc newVal*(s: BiggestInt): MinValue =
  return MinValue(kind: minInt, intVal: s)

proc newVal*(s: BiggestFloat): MinValue =
  return MinValue(kind: minFloat, floatVal: s)

proc newVal*(s: bool): MinValue =
  return MinValue(kind: minBool, boolVal: s)

proc newSym*(s: string): MinValue =
  return MinValue(kind: minSymbol, symVal: s)

proc isStringLike*(s: MinValue): bool =
  return s.isSymbol or s.isString or (s.isQuotation and s.qVal.len == 1 and s.qVal[0].isSymbol)

# Error Helpers

proc raiseInvalid*(msg: string) =
  raise MinInvalidError(msg: msg)

proc raiseUndefined*(msg: string) =
  raise MinUndefinedError(msg: msg)

proc raiseOutOfBounds*(msg: string) =
  raise MinOutOfBoundsError(msg: msg)

proc raiseRuntime*(msg: string, qVal: var seq[MinValue]) =
  raise MinRuntimeError(msg: msg, qVal: qVal)

proc getString*(v: MinValue): string =
  if v.isSymbol:
    return v.symVal
  elif v.isString:
    return v.strVal
  elif v.isQuotation:
    if v.qVal.len == 1:
      raiseInvalid("Quotation is not a quoted symbol")
    let sym = v.qVal[0]
    if sym.isSymbol:
      return v.symVal
    else:
      raiseInvalid("Quotation is not a quoted symbol")

proc warn*(s: string) =
  stderr.writeLine s

proc previous*(scope: ref MinScope): ref MinScope =
  if scope.parent.isNil:
    return ROOT
  else:
    return scope.parent

proc define*(name: string): ref MinScope =
  var scope = new MinScope
  scope.name = name
  scope.parent = INTERPRETER.scope
  return scope

proc symbol*(scope: ref MinScope, sym: string, p: MinOperator): ref MinScope =
  scope.symbols[sym] = p
  #if not scope.parent.isNil:
  #  scope.parent.symbols[scope.name & ":" & sym] = p
  return scope

proc sigil*(scope: ref MinScope, sym: string, p: MinOperator): ref MinScope =
  scope.previous.sigils[sym] = p
  return scope

proc finalize*(scope: ref MinScope) =
  var mdl = newSeq[MinValue](0).newVal
  mdl.scope = scope
  mdl.scope.previous.symbols[scope.name] = proc(i: In) =
    i.evaluating = true
    i.push mdl
    i.evaluating = false

template `<-`*[T](target, source: var T) =
  shallowCopy target, source

template alias*[T](varname: untyped, value: var T) =
  var varname {.inject.}: type(value)
  shallowCopy varname, value

proc to*(q: MinValue, T: typedesc): T =
  return cast[T](q.obj)

# Validators

proc reqBool*(i: var MinInterpreter, a: var MinValue) =
  a = i.pop
  if not a.isBool:
    raiseInvalid("A bool value is required on the stack")

proc reqTwoBools*(i: var MinInterpreter, a, b: var MinValue) =
  a = i.pop
  b = i.pop
  if not a.isBool or not b.isBool:
    raiseInvalid("Two bool values are required on the stack")

proc reqInt*(i: var MinInterpreter, a: var MinValue) =
  a = i.pop
  if not a.isInt:
    raiseInvalid("An integer is required on the stack")

proc reqTwoInts*(i: var MinInterpreter, a, b: var MinValue) =
  a = i.pop
  b = i.pop
  if not a.isInt or not b.isInt:
    raiseInvalid("Two integers are required on the stack")

proc reqQuotation*(i: var MinInterpreter, a: var MinValue) =
  a = i.pop
  if not a.isQuotation:
    raiseInvalid("A quotation is required on the stack")

proc reqIntAndQuotation*(i: var MinInterpreter, a, b: var MinValue) =
  a = i.pop
  b = i.pop
  if not (a.isInt and b.isQuotation):
    raiseInvalid("An integer and a quotation are required on the stack")

proc reqTwoNumbers*(i: var MinInterpreter, a, b: var MinValue) =
  a = i.pop
  b = i.pop
  if not (a.isNumber and b.isNumber):
    raiseInvalid("Two numbers are required on the stack")

proc reqTwoNumbersOrStrings*(i: var MinInterpreter, a, b: var MinValue) =
  a = i.pop
  b = i.pop
  if not (a.isString and b.isString or a.isNumber and b.isNumber):
    raiseInvalid("Two numbers or two strings are required on the stack")

proc reqString*(i: var MinInterpreter, a: var MinValue) =
  a = i.pop
  if not a.isString:
    raiseInvalid("A string is required on the stack")

proc reqStringOrQuotation*(i: var MinInterpreter, a: var MinValue) =
  a = i.pop
  if not a.isQuotation and not a.isString:
    raiseInvalid("A quotation or a string is required on the stack")

proc reqStringLike*(i: var MinInterpreter, a: var MinValue) =
  a = i.pop
  if not a.isStringLike:
    raiseInvalid("A symbol or a string is required on the stack")

proc reqTwoStrings*(i: var MinInterpreter, a, b: var MinValue) =
  a = i.pop
  b = i.pop
  if not a.isString or not b.isString:
    raiseInvalid("Two strings are required on the stack")

proc reqThreeStrings*(i: var MinInterpreter, a, b, c: var MinValue) =
  a = i.pop
  b = i.pop
  c = i.pop
  if not a.isString or not b.isString or not c.isString: 
    raiseInvalid("Three strings are required on the stack")

proc reqTwoQuotations*(i: var MinInterpreter, a, b: var MinValue) =
  a = i.pop
  b = i.pop
  if not a.isQuotation or not b.isQuotation:
    raiseInvalid("Two quotations are required on the stack")

proc reqTwoQuotationsOrStrings*(i: var MinInterpreter, a, b: var MinValue) =
  a = i.pop
  b = i.pop
  if not (a.isQuotation and b.isQuotation or a.isString and b.isString):
    raiseInvalid("Two quotations or two strings are required on the stack")

proc reqThreeQuotations*(i: var MinInterpreter, a, b, c: var MinValue) =
  a = i.pop
  b = i.pop
  c = i.pop
  if not a.isQuotation or not b.isQuotation or not c.isQuotation: 
    raiseInvalid("Three quotations are required on the stack")

proc reqFourQuotations*(i: var MinInterpreter, a, b, c, d: var MinValue) =
  a = i.pop
  b = i.pop
  c = i.pop
  d = i.pop
  if not a.isQuotation or not b.isQuotation or not c.isQuotation or not d.isQuotation:
    raiseInvalid("Four quotations are required on the stack")

proc reqTwoSimilarTypesNonSymbol*(i: var MinInterpreter, a, b: var MinValue) =
  a = i.pop
  b = i.pop
  if not ((a.kind == a.kind or (a.isNumber and a.isNumber)) and not a.isSymbol):
    raiseInvalid("Two non-symbol values of similar type are required on the stack")

proc reqObject*(i: var MinInterpreter, t: string, a: var MinValue) =
  a = i.pop
  if not a.isQuotation or a.objType.isNil or a.objType != t:
    raiseInvalid("A $1 object is required" % [t])